﻿/************************************************************************

   Extended Silverlight Toolkit

   Copyright (C) 2010-2012 Xceed Software Inc.

   This program is provided to you under the terms of the Microsoft Public
   License (Ms-PL) as published at http://extendedsilverlight.codeplex.com/license

   Please purchase a commercial version of this toolkit if you are using
   it in a commercial product. The commercial versions support the project,
   and also include more features for each control, priority support,
   source code, updates, removed watermark, and a proprietary license.

   Visit http://xceed.com and follow @datagrid on Twitter.

  **********************************************************************/

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Linq;
using System.Data.Services.Client;

namespace Xceed.Silverlight.Data
{
  internal class QueryableServiceHandler : QueryableHandler
  {
    private static readonly Guid GetItemCountCallId = DataUtils.CreateCallId();

    public QueryableServiceHandler( DataServiceQuery dataSource )
      : base( dataSource )
    {
    }

    public override ValueSource ItemCountSource
    {
      get
      {
        return ValueSource.ApproximateCalculation;
      }
    }

    public override bool IsFullySynchronized
    {
      get
      {
        return true;
      }
    }

    internal override void AddItemCountHint( int value, bool isMaximumValue )
    {
      if( m_countManager.AddItemCountHint( value, isMaximumValue ) )
      {
        this.RaiseItemCountChanged();
      }
    }

    public override IAsyncResult BeginGetItemCount( AsyncCallback userCallback, object asyncState )
    {
      return AsyncResultsExtensions.ExecuteSync( QueryableServiceHandler.GetItemCountCallId, userCallback, asyncState, new GetCountResult( m_countManager.ApproximateCount ) );
    }

    public override GetCountResult EndGetItemCount( IAsyncResult getCountAsyncResult )
    {
      getCountAsyncResult.ValidateCallEnd( QueryableServiceHandler.GetItemCountCallId );
      return getCountAsyncResult.GetCallResult<GetCountResult>();
    }

    private ApproximateCountManager m_countManager = new ApproximateCountManager();

  }
}
